Computers for Beginners/The Basics 

What is a computer?

Simply put, a computer is a machine that performs mathematical and logical calculations.

Brief History

A large computer used in the 1940's.

Computers, by our above definition, have been around for thousands of years. One of the earliest computers was the abacus, a series of beads arranged on metal rods. Beads could be slid back and forth to operate on numbers. This was a very rudimentary device and is not commonly thought of as a computer in modern times. Our idea of computers involves electricity and electronics.

Electricity makes computers much more efficient. The first computers used an incredible amount of electricity, which changed voltages in vacuum tubes to operate the computer. These computers were given instructions using punch cards, and were behemoths, taking up entire floors of buildings. Only the more privileged universities and government facilities had access to them.

In the 1960's, the vacuum tube was replaced by the integrated circuit and transistor. These greatly reduced the size and power consumption of computers. They were still very large by today's standards, but more institutions had access to computing power than ever before. At the end of the decade, the microchip was invented, which reduced the size of the computer even more.

By the end of the 1970's, computers were widespread in businesses. Using a computer involved typing on a terminal (a keyboard and monitor connected to a large central computer). Soon, parts became small enough to allow many users to have a computer at their home. Thus the Personal Computer, or PC, was born.

Since then, personal computer has have become tremendously more efficient. They are much smaller, and yet have seen extreme performance gains. In addition to these improvements, computers have become affordable enough for many families worldwide.

Hardware

Hardware is the stuff you can touch, as opposed to software which is abstract and exists only in a virtual world as computer code. Hardware is made of materials found in the universe and are subject to the laws of physics. Contrary to the latter, software is bound only by the creator's imagination and the user's willingness to believe what the creator 

The Peripherals

Peripherals are hardware attached to a computer, but external to the main case that houses the CPU, Hard drives, and other such equipment. They are basically devices that allow people to communicate to the computer. It is generally a good idea, although not as important as it used to be, to add and remove hardware from the computer while it is turned off. Things such as USB storage devices and keyboards/mice can generally be inserted and removed at a whim with no consequence, however more advanced things such as printers should be installed according to the manufacturer's instructions, which may include shutting down your computer.

Keyboard and Mouse

The keyboard and mouse are basic input devices.

Keyboard

A keyboard with a QWERTY layout.

The keyboard has keys that, when pressed, send information to the computer. The keyboard is the most widely used device for interacting with a computer, and even many modern operating systems, such as Microsoft Windows XP can be operated with nothing but the keyboard or little but the keyboard. The most commonly used keyboard, by far, is the QWERTY layout, which almost all keyboards sold use. This is the same layout as most typewriters sold within the last century. The second most common, but a very distant follower, is the Dvorak Simplified Keyboard. While this is technically better, the industry and consumer market as a whole has mostly rejected it.

The QWERTY keyboard was designed to prevent typewriters from jamming while keys were being pushed at a fast rate, by keeping keys as far apart as possible. The Dvorak keyboard layout was designed for computers, where this is obviously not a problem, and thus places the most commonly used keys where they are easy to reach, and because of that, quicker. However, because of the popularity QWERTY had, the Dvorak keyboard layout never became popular, for two main reasons. The first being that because most people already know how to use QWERTY keyboards, and people are thus unlikely to switch, and the second being that because most people know how to use a QWERTY keyboard, there is very little use of Dvorak.

It is generally advised that you use a QWERTY keyboard, as even though Dvorak users gain significantly faster typing speeds, the rarity of the layout makes it hard for people who use Dvorak to use most other computers.

Keyboards vary in appearance. Those attached to a desktop computer are frequently large with an additional number pad built in on the right side, while laptop keyboards are attached to the computer and are often much smaller. Some keyboards also offer special buttons to control the mouse on the screen or to play music.

Mouse

A three button mouse.

The mouse is an input device which is primarily used by physically moving the device across a surface, which causes a pointer symbol, called a "cursor", to move across the screen, and secondarily by pressing a button while the cursor is over an object on the monitor, or "clicking". All mice have at least one button, with the most common layout having three.

• One button mice: The Apple mighty mouse is the only mouse known to most people which uses a single button. This button is usually activated by pushing on the front of the mouse, or pushing the entire mouse down. This has the benefit of being a simpler interface, and arguably more attractive, but suffers from this of being slightly more of a hassle to use, with tradition "right click" needs being changed to pressing a "control" or "ctrl" key on the keyboard while pressing the main button. These are only used with Macintosh OS, such as Mac OS X.

• Two button mice: The second most common layout, more common in older computers, which has a button on the left and right, usually for the index and middle finger. While less useful than a three button mouse, they are, when teamed with a standard keyboard, capable of performing almost all computer tasks.

• Three button mice: The most common layout, Fundamentally the same as a two button mice, but with a third button added between the "left" and "right" click buttons. While the mouse technically has three buttons, this may be confusing to some users, as the "middle"/"center" click button is also a scroll wheel. This design allows the user to scroll through documents, make selections, and do other tasks by moving a finger, rather than pressing an arrow key or "Page up/Page down" key on a keyboard. The center button can also be press inwards to create a "middle click" button, which although not common, is used in some programs to perform a simple function, such as the Firefox web browser, which uses the middle click to open a link in a new tab.

• Four (or more) button mice: Usually seen only on gaming and multimedia specialization mice, extra buttons generally do not serve any native purpose, and rather are assigned a function to perform by the user. For example, a user who uses the mouse to play games might assign the additional buttons to switch between weapons in a shooter, or cast spells in a fantasy game.

There are two other major differences in mice, which is Optical/Laser mice, and Ball mice. This is how the mice tells where it is, with the laser measuring the distance it crosses when it is moved, and the ball measuring how it rotates. The laser is generally more accurate and less of a hassle to use, and can be used on more surfaces, but the ball mouse is cheaper. Ball mouse are rarely seen today.

The last important consideration when buying a mouse is size. You should always try to put your hand on a mouse and move it around, to see how well it feels in your hand. If it feels awkward, small, big, long, or short, look for something better! Not only will your hands thank you, but you will be more efficient.

Media Devices (Floppy, CD-ROM, DVD, USB)

These devices carry data, in the same way that a hard drive does, but are much more portable. They are the primary method of storing data outside of a computer, and the main method of transferring information between computers without the use of a network, such as the internet.

There are three main types of these in use today:

• CD-ROM: Capable of storing 700MB of data, CDs have been the most common method of storing data for most of the last decade or so. They are being largely replaced by DVDs and USB drives (see below).
• DVD: Capable of storing 4.7GB of data in their single layer form and 8.5GB in their double layer form, they are the most common method today for most store-bought programs, as well as videos.
• USB/Flash: While not usually used by commercial software, USB 'sticks' and Flash 'cards' have become popular ways of storing data because of their ease of use and low cost. While sizes range from 2GB on old units to 256GB on larger, more expensive modern units, the average stick today is 4 or 8GB, with an average 4GB USB stick costing about 15$ US.

The floppy disk has been phased out.

Monitor

The monitor is the main method for the computer to produce output, in the same way a book has pages. A book filled with letters, but in a way you can't possible understand or even see is of no use to you, and the same is true for a computer. While older monitors, CRTs, were rather bulky like TVs, newer monitors, or LCDs, are much more compact, and can be easily lifted.

For much of the history of computers, the most common monitors were CRTs, short for Cathode Ray Tubes. They work on the same principle as a television. They were generally heavy, had a lower image quality, and were in general less reliable than an LCD. They come in two forms, the normal version, which has a curved monitor, and "Flat Screen", where the display is completely level (although it still has the bulky back end). It is suggested that if you plan to remove a CRT, it is better for the environment to safely dispose of it (not just into a bin, an electronic waste bin), as CRT's contain high levels of toxic chemicals. The most common type of monitor today is an LCD, or Liquid Crystal Display, which is much lighter, although slightly more expensive. They have a smaller form, a higher image quality, and are overall better than CRT monitors.

Tip: To take proper care of your monitor, always be sure that the screen is not left on a static image for long periods of time. This can "burn" the image into the monitor, meaning that it will have a ghosting effect, even when that image is not displayed. This can not only be highly annoying, but in some cases, make it so the monitor needs to be replaced. To avoid this, either set a moving screensaver, which will trigger after a set amount of time, or simply turn the monitor off

Printer

If you have a printer attached to your computer you can print your information and keep a physical copy of data. Depending on what type of printer you have, you can print in color, double-sided or book form. The output quality of some printers goes from draft (to save ink) all the way to photo quality.

Printers come in all price ranges and in many types. The most common for home use are ink jets (bubble jets) and laser. There are specialized printers for data plotting (mapping), photos only, labels and more.

A lot of printers are "all-in-ones" which simply means they combine more than one function. They can be any combination of printer, copier, fax and scanner. If you are looking to buy an all-in-one make sure it has all the features you are looking for. You don't want to get it home and find out you still need a separate fax machine or scanner that you thought was included!

Basic Operating Tasks

Moving the Mouse

The mouse controls the movement of an on-screen pointer, called the cursor, that often appears as a small white arrow. When you move the mouse, the pointer on-screen moves too, usually in the same direction as the mouse. In other words, move the mouse toward you to move the on-screen pointer toward the bottom of the screen, you move the mouse to the away from you and the arrow moves to the top, and so on. You indicate to the computer what parts of the screen you want to interact with by placing the pointer over those areas on the screen.

Keyboard

The keyboard is used for inputing text into the computer. It is designed so that users can type all the letters of the alphabet without moving their hands. Many programs from word processors, media players utilize the keyboard.

• The numbers at the right of the keyboard can work in two ways. While in normal mode, the keys will function as another set of arrow keys, in num lock mode, they will instead be an alternate way of inputting numbers. This is mainly useful when putting in more than a few digits at a time, when using the numbers over the letters becomes more of a hassle than a time saving method.

• The keys labeled F1, F2, F3 ... at the top of the keyboard are the "function keys". F1 is usually assigned as a "help" key, which will open a help dialog when pressed. If you are having trouble with a program, or just want tips, reading these files can often be useful or insightful.

• "Ctrl" and "Alt" at the bottom means "control" and "alternative". These keys are normally used to type special symbols or for shortcuts. More on that below.